Learning and Memory Flashcards
learning, memory
- learning- acquisition of new info
- memory- retention of new info
procedural memory
(implicit, non-declarative)
- reflexive memory
- skills and habits that have been used so much they are automatic
- cerebellum- motor skills
- nucleus accumbens- non-motor
declarative memory
(explicit)
- conscious recognition/recollection of learned facts and experiences
- episodic- memory of events
- semantic- memory of words, language, rules
short-term, long-term, working memory
- short-term- secs to hrs
- long-term- yrs
- working memory- recalling a fact/memory for use
production of memory and learning requires what?
-neuronal and synaptic plasticity
plasticity
alterations in the CNS based on use
- synaptic fxn
- physical structure of neurons (more synapses, more branches to new cells)
plasticity- Changes in synaptic fxning
- post-tetanic potentiation
- pre-synaptic facilitation
- LTP (long-term potentiation)
plasticity- changes in structure of neurons
- gain/loss of synapses
- structural changes in dendrites
- structural changes in soma of neuron
post-tetanic potentiation
- brief, high-freq discharge of presynaptic neuron
- inc NT release
- lasts 60 seconds
post-tetanic potentiation- mech
-AP goes down axon- Ca enters- more vesicles fuse w cell membrane- greater Nt release
presynaptic facilitation- mech
- normal synapse
- add another neuron that synapses on the presynaptic terminal of neuron A
- when act, these terminal releases 5HT
- act of AC and inc CAMP
- K channels in Neuron A become phosphorylated- opening is delayed- repolarization is delayed
- greater Nt release
LTP (long-term potentiation)
- changes in pre- and post-synaptic neurons of a synapse that lead to inc response to release Nt
- inc in response lasts HRS after the stimulation
LTP- mech
- Mg blocks the EAA channel- when depolarized, Mg leaves- Ca, Na enters channel
- Ca-> calmodulin-> inc AC/caMP-> phosphorylation of AMPA R-> inc Na influx in response to EAA
- Ca-> calcineurin-> act of NO synthase-> NO-> to pre-synaptic cell: inc cGMP, inc NT release
- inc CREB- gene transcription
learning and form of new memories can be blocked by?
blocked prot syn
inc CREB- causes what?
gene transcription- prot syn:
- NT synthetic enzymes
- NT Rs
- proteins required for growth/synapse formation
Creating Declarative (Explicit) Memories- steps
- encoding (attending to new info)
- storage of info
- consolidation- making a memory permanent (physical changes in synaptic structure)
- retrieval- working memory
Short-term memory- storage- anatomical substrate
Temporary storage:
- hippocampus
- parahippocampal cortex
- prefrontal cortex
- interconnections to neocortex and amygdala via nucleus basalis of Meynert (cholinergic projection- target of Alzheimer’s dz)
Short-term memory- physiological substrate
- LTP
* temporary storehouse for memory
Consolidating memory from short to long-term- requires?
- hippocampus
- temporal lobes
- papez circuit
Consolidating memory from short to long-term- physiology
- memory is repeatedly sent thru the Papez circuit- induce LTP and neuronal plasticity
- creates new synapses in required regions of brain (visual, auditory)
- hypothalamus-> ant thalamus-> cingulate cortex-> hippocampus->
long-term memory- stored where?
-area of cortex related to the modality of the individual components (ex- visual info is stored in visual cortex)
Long-term memory- reassembling- requires?
- neocortex
- parahippocampal regions
- hippocampus
Recalling/retrieving memories
- info related to each component of the memory is sent to parahippocampal regions
- then to hippocampus- entire memory is reconstructed
- back thru parahippocampus to cortex (keeps the trace)
working memory- 3 component model
- visuospatial loop- occipital cortex assoc w vision
- central executive- prefrontal cortex
- phonological loop- Broca’s and Wernicke’s
Spatial memory
- stored in hippocampus- uses place cells (in CA1)
- spatial map serves as an anchor for the reconstruction of memory
